Linked Life Data

8117661

Source:http://linkedlifedata.com/resource/pubmed/id/8117661

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1994-4-4
pubmed:abstractText
ATP sulfurylase from Escherichia coli K12 catalyzes two, coupled reactions: the hydrolysis of GTP and the formation of activated sulfate (APS). At saturating levels of GTP, the initial rate of APS formation is stimulated 116-fold. The mechanism of this activation has been investigated using isotope trapping, mass spectrometry, and initial velocity kinetic techniques. In the presence of GTP, APS formation proceeds via nucleophilic attack of sulfate at the alpha-phosphoryl group of ATP. Isotope-trapping experiments demonstrate productive, random binding of ATP and GTP. ATP is hydrolyzed to yield AMP and PPi. AMP production requires GTP and is suppressible by sulfate, suggesting GTP-dependent formation of an E*AMP intermediate in the synthesis of APS. Studies using the hydrolysis-resistant nucleotide analogues AMPCPP and GMPPNP demonstrate that GTP hydrolysis precedes scision of the alpha-beta bond of ATP. Product inhibition studies indicate that PPi release occurs prior to the addition of sulfate and APS formation. These results are used to construct a proposed mechanism for the GTP-activated synthesis of APS.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2042-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
GTPase activation of ATP sulfurylase: the mechanism.
pubmed:affiliation
Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.